Modern golf clubs, particularly those adapted for use as putters, vary widely in concept and design. A typical putter configuration is one in which the putter head has a generally vertical face (when the player addresses the ball) and a rearward portion which incorporates a cavity or recess of some sort which is located behind the face of the putter. These cavities can be configured or used in a number of ways in order to provide clubs, which are designed to accommodate various modifications or adjustments in the putter head or simply to incorporate what is considered to be an advantageous design, to aid the golfer in his making accurate putts. For example, U.S. Pat. No. 5,308,068 to Strand discloses a golf putter which has a vertically-oriented front plate which provides a ball-striking surface and a rearwardly-extending, generally horizontally-oriented, sole plate which extends backwardly from the front plate. The sole plate and the front plate form to provide a generally L-shaped head with the back of the front plate and the top of the sole plate defining a cavity or recess behind the ball striking surface. In the Strand putter, weights are provided at the toe and heel portions of the putter. The top surface of the sole plate is provided with aiming indicia at approximately the center of mass of the putter head taking into account the front plate, the sole plate, the two end weights at the heel and toe, and the hosel which provides an interconnection between the putter head and the hand shaft of the putter. The hosel is connected to the heel weight at a location to the rear of the front plate. The hosel provides a connection which is bent inwardly and then upwardly and outwardly in a gooseneck configuration to provide a shaft which ultimately terminates in a handle which is located forward of the striking face of the putter. Thus, when the golfer addresses the ball, his hands are forward of the striking surface and the golfer has a stance in which he has a clear view of the ball and the striking surface of the putter. The shaft itself is configured so that an extension of the shaft axis will fall behind the putter head at a location between the center mass of the putter face and the heel portion of the putter.
Another putter head, incorporating a rearwardly-facing cavity or recess, said to be useful in providing a number of functions, is disclosed in U.S. Pat. No. 4,655,459 to Antonious. In Antonious, the rearwardly-facing cavity is provided behind the front-striking face of the putter and extends between heel and toe portions which themselves are provided with cavities, in this case downwardly-facing cavities. This combination of a centrally-located, upwardly-facing cavity and two downwardly-facing cavities at the head and toe of the putter is described as providing a unique weight distribution system which is said to counteract the effect of torque when the ball is stroked off-center. Weights can be provided at the bottom of the upwardly-facing cavity and at the top of the downwardly-facing cavities. Alternatively, lead shot can be incorporated into the cavities and the cavities then closed by plates. Here, the club shaft is secured to the heel portion of the club head in conventional fashion.
Yet another golf club incorporating a head having a plurality of cavities, in this case two rearwardly-facing cavities opening at the top, is disclosed in U.S. Pat. No. 5,518,235 to Mendenhall. In the Mendenhall club, the putter head is provided in the back portion of the head with three struts which define two cavities. One strut is at the heel portion of the club, another at the toe portion, and the third or center strut is located about halfway between the heel and toe and has a notch in its upper surface to identify the "sweet spot" of the putter head. The proximal and distal struts at the head and toe of the putter slope downwardly and backwardly in what is described as an S-type configuration. The proximal strut at the heel of the club is provided with a rectangular aperture which extends fore and aft through the club from the front face of the club head to the rear surface of the strut. This aperture receives an arm of a corresponding rectangular configuration which serves to connect the hosel of the club shaft to the front face of the putter. The hosel terminates in a socket which receives the club shaft in a manner so that it is generally aligned in a plane which is parallel to the striking pad and extends through the center line of the ball being addressed by the club head. While the proximal and distal struts slope downwardly in the S-shaped surface described previously, the center strut extends throughout its full height for most of its rearward extension so that it provides a substantially greater mass than the proximal and distal struts.
Yet another putter configuration in which a rearwardly-facing cavity is provided to accommodate an adjustable weight at various locations along the club head is disclosed in U.S. Pat. No. 5,390,939 to Stubbs. This patent discloses a putter head which is characterized as symmetrical (for use as a right- or left-handed putter) in that the toe and head portions are the same and may be provided with press-fitted brass weights. The front face of the club is provided with a number of transversely-located bores which can be used with pins to locate a block member at any one of several transverse locations along the club head. A hosel member in turn can be secured to the back of the block member in an orientation in which the hosel and, therefore, the club shaft can be adjusted to provide for use by a right- or left-handed golfer.
Finally, U.S. Pat. No. 4,265,451 to Bernhardt discloses a putter in which the club head is configured to provide recesses which are located on either side, one near the heel and the other near the toe of the interconnection between the club face and the neck member used to secure the shaft to the club head. This design is said to produce a distribution or weight which produces an acceptable stroke at any point of impact across the entire area of the ball-striking surface.